VOL. XXXVII, No. 434^ 



February, 1903 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 



TO THE NATURAL SCIENCES 

 IN THEIR WIDEST SENSE 



CONTENTS 



Page 



I. The Structure and Relationships of the American Pelycosauria E. C. CASE 85 



II. Notes on the Unionids and their Classification V. STEBKI 103 



HI. A Paraffine Bath heated by Electricity .... Professor E. L. MARK 115 



IV. Notes and Literature: Zoology, Development of Cribella, Studies of 121 



Recent Brachiopoda, Salmon and Trout, Boulenger on the Relationship 

 of the Flounders, Boulenger on Selenichthyes, Meek on Fishes of Mexico. 

 Fishes of Formosa, Fishes of Japan, Notes on Recent Fish l iterature. 

 Hay on Fossil Vertebrates, Notes - Botany, Mcllvaine and Macadams 189 



V. Quarterly Record of Gifts, Appointments, Retirements and Deaths 149 



GINN & COMPANY, PUBLISHERS 



